Magnetic switch
When the magnetic switch switches are referred to either a magnetic element switch or a magnetic field are switched.
Until the middle of the 20th century, 'magnetic switch ' was the German term for a relay , simple electromagnetically switched changeover switches or single-pole on-off switches. Today, however, the word relay has fully established itself for this . Under magnetic switch in the broad sense refers to all types of switches with magnetic effectiveness.
Examples:
- As part of the starter of internal combustion engines: As soon as current flows through the winding of the magnetic switch, it first engages the starter pinion in the teeth of the flywheel of the internal combustion engine and then closes a contact so that the electric motor of the starter is energized. The starter then drives the combustion engine until it can continue to run independently.
- A switch that reacts to a magnetic field, such as a reed contact or a Hall sensor . A common application is the detection of open or closed doors in automobiles or buildings. A permanent magnet is attached to the door leaf so that its magnetic field triggers the switch when the door is closed. The switching signal is evaluated by a higher-level controller such as an alarm system .
- The magnetic switch can also be attached to doors and windows in such a way that it does not switch when the sash is closed, but only when it has been locked by operating the window handle or the door key. This so-called "combined opening and locking monitoring" is used in connection with alarm systems, with a ventilation control or in building automation and has the advantage that opening and locking are monitored with just one switch.
- The Google Cardboard (a glasses frame for virtual reality applications) uses a manually movable magnetic ring to act on the sensor ( compass ) of a smartphone.
